Hi, thanks that you take a look at this. I'm not a programmer and I really don't know how to compile it.
At least if someone would read the source code he could tell how Garmin store the maps. Maybe only a little change in the code would also extract the one-way street information. I'm sure that the information is included in the dataset on the CD, since the maps are used for routing.
I've seen some example pdf files in the package and some text files with road names.